//
//  MainTabBar.swift
//  微博项目
//
//  Created by mac on 16/1/11.
//  Copyright © 2016年 mac. All rights reserved.
//

import UIKit

class MainTabBar: UITabBar {

    
    
    //懒加载获取加号按钮
    lazy var plusBtn: UIButton = {
        //UIButton() 会得到一个 自定义类型按钮
        let btn = UIButton()
        //设置按钮的背景图片
        btn.setBackgroundImage(UIImage(named: "tabbar_compose_button"), forState: .Normal)
        btn.setBackgroundImage(UIImage(named: "tabbar_compose_button_highlighted"), forState: .Highlighted)
        //设置按钮的图片
        btn.setImage(UIImage(named: "tabbar_compose_icon_add"), forState: .Normal)
        btn.setImage(UIImage(named: "tabbar_compose_icon_add_highlighted"), forState: .Highlighted)
        //自适应大小 懒加载本质是一个 闭包 需要加self
        btn.sizeToFit()
        return btn
        }()

    //1.
    override init(frame: CGRect) {
        super.init(frame: frame)
        addSubview(plusBtn)
        
    }

    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
    
    //2.
    override func layoutSubviews() {
        super.layoutSubviews()
        
        let w = self.bounds.width/5
        let h = self.bounds.height
        let rect = CGRect(x: 0, y: 0, width:w, height: h)
//
//        
        var index :CGFloat = 0
       
        for subView in subviews {
            if subView.isKindOfClass(NSClassFromString("UITabBarButton")!){
            
            subView.frame = CGRectOffset(rect, index * w, 0)
                
                if index == 1 {
                index++
                }
                index++
            }
        
        }
        plusBtn.frame = CGRectOffset(rect, 2 * w, 0)
        
    }
}
